Building Management Systems (BMS)

Seminar 1 – The Basics Explained

Presented By: Andrew Smith Leader Building Technologies – A.G. Coombs Advisory

Seminar 1 – The Basics Explained 1) What is a BMS? 2) What Does it Do? 3) Benefits 4) Operational Considerations

Seminar 2 - Advanced Management and Improvement Opportunities 5) BMS System Architecture 6) BMS Programming 7) Extended BMS Functionality 8) Upgrades and Retrofits

1. What is a BMS?

Industry jargon, Terminology and acronyms What is a Building Management and Controls System BMS suppliers and integrators Typical System Components Typical User Interface Options

Industry Jargon, Terminology and Acronyms • Building Management Systems (BMS) also known as Building Automation

Systems (BAS), Building Management and Control System (BMCS), Direct Digital Controls (DDC) and Building Controls

• Other terms associated with Control Systems include: – Supervisory, Control and Data Acquisition (SCADA) – Programmable Logic Controllers (PLC) – Energy Management System (EMS) – Data gathering panels (DGP) – Modbus, Lonworks, and Bacnet – All refer to communications protocols – ‘Front End’ – legacy term used to refer to the BMS Operator Workstation

• Most Common Current industry term – – Building Management System (BMS) or – Building Management and Control Systems (BMCS)

What is a Building Management System? • BMS systems are “Intelligent” microprocessor based controller networks

installed to monitor and control a buildings technical systems and services such as air conditioning, ventilation, lighting and hydraulics.

• More specifically they link the functionality of individual pieces of building equipment so that they operate as one complete integrated system.

• Now installed in every major building or facility with the availability of direct integration into all other building services such as security, access control, CCTV, fire, Lifts and other life and safety systems.

• Current generation BMS systems are now based on open communications protocols and are WEB enabled allowing integration of systems from multiple system vendors and access from anywhere in the world.

What Does Intelligent Microprocessor Control Mean?

OUTPUTS

INPUTS

NETWORK

What Does Intelligent Microprocessor Control Mean?

OUTPUTS

INPUTS

NETWORK

BMS Suppliers and Integrators • Procured as a complete system that includes, engineering, supply,

installation, programming and commissioning. • Specialist Integrators that are either directly associated with the

manufacturer or are approved re-sellers.

• All Integrators should have full factory technical support

• Need to work closely with Mechanical Services, Mechanical Electrical and other contractors.

• For new construction BMS is usually included within the mechanical services package.

• ‘Tier 1 Company’ only refers to a direct factory association and not to the quality of products or services…

Typical System Components – BMS Hardware

Operator Workstations

Range to Suit Applications

Built In Displays

High Point Counts

Small Point Counts Application Specific

Limited Features

Typical System Components – Field Devices

Temperature Relative Humidity CO2

Low Level and High Level (HLI) Connections

Voltages Currents

Water Flows Pressures

Air Flows Pressures

Variable Speed Drives (VSD)

Pumps Fans Motors

Damper Actuators

Valve Actuators

Chillers / Boilers Cooling Towers

Typical System Components - Networks

Typical User Interface Options Can be a basic LCD display through to

full Graphic Operator Workstations.

The Graphic Interface must be intuitive to use and not require an Engineering degree to interpret

They must provide sufficient level of detail to enable the operator to determine what is happening and what is going to happen next

Graphics need to provide access to parameters for tuning and seasonal information needs to be built into the system

BMS Simple User Interfaces – Built in Display

User defined menus. Built into the BMS controller or a

remote device Password protected Monitor and control field points,

operating setpoints, time schedules, alarm management, even trend data

BMS Simple User Interfaces – WEB Server

WEB Server built into a BMS network controller

User defined menus and graphic pages

Password protected, multiple access levels

Monitor and control field points, operating setpoints, time schedules, alarm management, even trend data

2. What Does a BMS Do?

The role of the BMS in day to day building operation Building Control Applications Measuring and Monitoring building performance Interaction with other building systems

The Day to Day Role of the BMS… • The most common primary function of

the BMS is the control of a buildings Heating, Ventilation and Air Conditioning Systems (HVAC) including; – Air Handling Units – Chilled Water Plant – Cooling Towers – Tenant Condenser Water – Heating Water Plant – Exhaust Systems – Zone Controls – Computer Room AC

The Day to Day Role of the BMS… • Control of Building Systems and Services • Graphic User Interface (GUI) • Real Time Monitoring of Building Operation and Performance • Trending and Logging of Building Operation and Performance • Time Scheduling of Building Systems • Fault Management and Alarming • Control Application Programming • User Event Management • Energy Management and Reporting (NABERS)

Building Control Applications

• Building control applications include for following: – Zone temperature monitoring and control – Zone Variable Air Volume (VAV) control to zones – Zone CO2 monitoring and control (Air Quality) – Air handling unit supply air temperature control – Air handling unit supply air flow / pressure control – Main Plant Chiller and Boiler sequencing – Toilet, car park, kitchen and general exhaust fan control – After Hours Building Control

Interaction With Other Building Systems

3. Benefits of Having a BMS

The advantages of a BMS versus stand alone control Improved Tenant comfort conditions Energy Management and reduced operational costs Management of building ratings such as NABERS

Advantages of BMS vs Stand Alone Control • Reduced installation costs • Flexibility and ease of change • Customised control strategies • Scalability • Operator interaction,

feedback and control • Integration with other

building services

Improved Tenant Comfort Conditions • Real time monitoring of tenant conditions • Greater load based control strategies • Trend data of performance, improved fault finding • Air quality management (CO2) • After hours operational requests, tenant billing • Alarm notifications of faults reduce downtime • Automated change over of failed equipment

Energy Management and Reduce Operational Costs • Optimal start and stop of plant • Building warm up and cool down cycles • Night purge • Automatic Seasonal plant sequence selection • Seasonal temperature setting adjustments • Load based control strategies • Economy cycle control including CO2 • Equipment runtime monitoring and duty cycling • Occupancy control and control setback

Management of Building Ratings - NABERS • Can be integrated with Energy Management System (EMS) • Real time monitoring of energy performance • Proactive adjustment not retrospective catch up • Measurement against load profile targets • Separation of tenant and base building loads • Historical trend data for NABERS management • Energy demand and consumption dashboards

• EMS is a dedicated software packed for the monitoring and management of electrical,

water, gas and thermal energy metering systems.

Management of Building Ratings - NABERS

4. Operational Considerations

Tuning and optimisation Importance of System Documentation System Maintenance, what, how often and by whom Life cycle expectations and considerations

Control Loop Tuning • BMS Tuning and Optimisation are not

the same thing….

• BMS Tuning or control loop tuning ensures that the equipment operates in a stable, predictable and repeatable manner.

• Optimisation focuses on operating the equipment in the most energy efficient manner without impacting on the controlled variable

• The first stage of optimisation includes BMS loop tuning.

Control Loop Optimisation Outside Air Temp 17C

Chiller Running Supply Air Temp 14C Static Pressure 350pa VSD Running at 95%

VAV Damper 15% Open

Zone Temp 22C

Chiller Stopped Supply Air Temp 18C Static Pressure 200pa VSD Running at 75%

VAV Damper 85% Open

Zone Temp 22C

VAV Damper 55% Open

Importance of System Documentation • Functional Description (FD)

– Details the configuration of the BMS – Overview of the building services – Describes in detail each of the BMS control strategies and sequences of

operation – Documents interaction between each part of the system

• Point Schedules

– Detail all connected devices and their point type – Critical for planning and system engineering

• Control System Drawings

– Should include a network architecture drawing – Detail the physical wiring connections to controllers – Useful for fault finding and establishing spare capacity

Importance of System Documentation Point Description DI DO AI AO HLI Comments

Chiller HLI 2 Modbus Connection to Chiller Chiller enable 2 Chiller run status 2 Chiller fault status 2 CHW Pump start / stop 2 At MSSB CHW Pump run status 2 CHW Pump speed control 2 Direct to VSDs CHW Flow temperature 2 CHW return temperature 1 CHW system pressure 1 CHW bypass valve 1 Tenant Cooling Tower Fans Start / Stop 2 Tenant Cooling Tower Fans Status 2 Tenant Cooling Tower Fans Speed 2 Tenant Cooling Tower Spray Start / Stop 2 Tenant Cooling Tower Spray Status 2 Tenant CCW System Pressure 1 Tenant CCW Pump start / stop 2 Tenant CCW Pump run status 2 Tenant CCW Pump speed control 2 Tenant CCW Flow temperature 1 Tenant CCW return temperature 1

Totals 12 10 7 7 2

DI – Digital Inputs DO – Digital Outputs AI – Analogue Input AO – Analogue Output HLI – High Level Interface

BMS Drawings show device details and wiring connections

System Maintenance • The BMS belongs to the building owner who should act as its

administrator managing BMS access rights • The BMS should be maintained with an appropriate level of servicing • As with any software driven system, data and files should be backed up on

a regular basis • Critical components should be identified and checked at regular intervals • BMS functions such as trend data, reports and alarms can be used to

perform maintenance by exception • Maintenance should be approached as the performance of the controlled

system not individual components, i.e. AHU or Chiller Plant • While the BMS equipment vendor should be utilised to maintain the

critical components, other suitably qualified technicians can be utilised for field equipment

BMS Lifecycle Considerations • Considerations:

– Check equipment production cycle status – Select hardware with proven record (avoid beta) – Check for level of software and hardware support – Check for forward compatibility policy

• Equipment Lifecycle:

– BMS field controllers – 15 to 20 years – Field devices – 15 to 20 years – BMS computer hardware – 3 to 5 years – BMS software – Major releases 3 to 5 years

BMS The Basics Explained – Recap… • BMS systems are “Intelligent” microprocessor based controller networks

installed to monitor and control a buildings technical systems and services such as air conditioning, ventilation, lighting and hydraulics.

• Scalable from just one device to thousands of devices

• Link the functionality of individual pieces of building equipment so that they operate as one complete integrated system.

• Provide the building owners and operators with the tools to manage the performance and energy efficiency of their buildings

• Can be integrated into all other building services such as security, access control, CCTV, fire, Lifts and other life and safety systems.